The pilots of a Russian An-28 turboprop that crashed last month both had alcohol in their blood, investigators said. But it is unclear whether their apparent intoxication was a factor in the crash, which killed 10 people when the plane went down in a forest about five miles from its destination, a small airport in the far eastern part of the country. Investigators said one pilot had a “low level” of intoxication, while the other had a “medium level,” but did not provide estimated blood alcohol content numbers or other figures. And it’s not clear exactly why the plane went down, or whether mechanical issues or weather could have played a role. But investigators said neither pilot should have been allowed to board the plane and depart with their levels of intoxication. In recent years, several crashes in Russia have been blamed on drunken pilots, including the July 2011 crash of a Russian jet that killed 47 people.